1. Field of the Invention
This invention relates to a cogeneration system, particularly to a cogeneration system combined with a solar electric generation system in an efficient manner.
2. Description of the Related Art
In recent years, cogeneration systems have been developed that are equipped with an internal combustion engine-driven generator for supplying power to the load and also for supplying hot water or air or the like, heated by using exhaust heat from the engine to a thermal load. Further, a cogeneration system combined with a solar electric generation system is disclosed in Japanese Laid-Open Patent Application No. Hei 11 (1999)-55860.
The cogeneration system taught in the reference includes a sunlight cogeneration system utilizing solar electric generation to generate DC power, an engine cogeneration system utilizing engine electric generation to generate DC power, and an inverter that inverts generated DC power to AC power to be supplied to electrical loads. Since the output of the sunlight cogeneration system fluctuates depending on hours of sunlight, the sunlight cogeneration output is monitored and if it drops, the engine cogeneration system is operated to increase its output.
In this system, since the sunlight cogeneration system and the engine cogeneration system are independent from each other, it is disadvantageously complicated, although they share the inverter.